More Sleep Means More Focused, Emotionally Stable Kids

How important is sleep for children? Getting too little could leave them more emotional and impulsive.

As a nation, we don’t get enough sleep. And we’re passing along our night-owl habits to members of the next generation, which could leave them with less control over their emotions and more prone to impulsivity, according to the latest study.

Lead author Reut Gruber, a psychologist at McGill University, and her colleagues describe in the journal Pediatrics a study in which they either added or deprived healthy children ages 7 to 11 of one hour of sleep a night over five nights. Their goal, says Gruber, was to see if such modest changes in the amount of sleep children get could affect their behavior. The children’s teachers were asked to fill out a 10-item standard questionnaire to assess the children’s attention, impulsivity, irritability and emotional reactivity at the end of the study period.

Compared with their same ratings during an initial five days of unmanipulated sleep — in which the researchers asked parents to allow the children to sleep as they normally would to establish a baseline — those who were deprived of an hour’s sleep had worse scores on behavior measures than those who were allowed to sleep an hour more. (The parents were asked to change their children’s bed times, and while they were able to put the kids to bed an hour earlier when needed, the youngsters ended up sleeping only about 30 minutes more.) In terms of how emotionally reactive, or sensitive, and how attentive the children were, teachers rated the sleep-restricted students on average 4 points higher than their baseline, meaning they showed more irritability, frustration and had more problems paying attention. In contrast, the children who slept more showed an average 3-point drop in these problems.

“Nobody became a genius, and nobody became crazy,” says Gruber, “but the findings show that in children small changes can make a big difference, and that is why this is meaningful.”

The scientists intentionally conducted their study outside of the lab, in the real-life setting of the children’s homes and schools, because they wanted to assess how everyday changes — which could involve losing an hour or gaining an hour of sleep — might impact children’s behavior in the classroom. One more movie or one less game played before bed can translate into potentially significant changes in the way children focus and interact with their teachers and classmates, says Gruber.

If being deprived of sleep leads to a drop in attention in class, children may miss out on learning and on opportunities to be creative. And if they are easily irritated and frustrated because their bodies and brains are tired, they may not learn as much either.

In previous research, Gruber and her colleagues looked at children who were at various stages on the attention-deficit/hyperactivity disorder spectrum and performed a similar study in which she asked parents to put the children to bed about an hour later than they normally would. The children completed computerized tests of attention both before and after the sleep intervention. Afterward, two-thirds of those who were teetering on the threshold of clinical disease were pushed into a definitive diagnosis, triggered by the sleep deprivation.

“Between these two studies, to me this connection feels like a real finding,” says Gruber. “Of course, we want to replicate the results and do more analysis.”

In the meantime, it’s clear that even modest changes in sleep — one less movie or video game — can affect the way children react to their world, and that in turn can affect their ability to learn and form relationships with others. Sleep, it seems, is just as important as diet and exercise in keeping children’s bodies and minds healthy. “We could have really significant positive and negative impacts on children depending on how we choose to prioritize sleep,” says Gruber. Got sleep, anyone?